Blood Pressure Measurement vs. Notification Devices: Understanding the FDA Distinction

Introduction: The Importance of Clarity in Blood Pressure Device and Software Classification 

As wearable technology advances, more devices are integrating blood pressure features—from clinical-grade monitors to smartwatches that “notify” users of potential changes. But not all blood pressure devices are created—or regulated—the same. 

Understanding the difference between a blood pressure measurement device (FDA product code DXN) and a hypertension machine learning-based notification software (FDA product code SFR) is crucial for product developers and regulatory teams alike. 

These classifications define how a device or software is developed and verified, from design and clinical testing to the level of evidence required for regulatory submission and ultimately determine how it can be marketed and used by the end user. 

Noninvasive Blood Pressure Measurement System (DXN) 

Devices classified under FDA product code DXN are blood pressure measurement devices. These systems are designed to generate quantitative blood pressure values, typically systolic and diastolic readings, used for medical assessment and decision-making. They employ noninvasive methods such as inflatable cuffs or optical sensors to detect arterial pressure changes. 

Key Characteristics of Devices: 

• Provides quantitative systolic and diastolic blood pressure values; some also estimate mean arterial pressure (MAP). 

• Must meet performance and accuracy standards such as ISO 81060-2 (non-invasive sphygmomanometers) or ISO 81060-7 (cuffless devices) 

• Requires clinical validation studies to demonstrate accuracy across a range of ages, sex, arm circumferences, and blood pressure ranges (hypotension and hypertension) 

• Must be validated against a reference standard (e.g., dual-listener auscultation or intra-arterial line) 

• Used for clinical assessment, patient monitoring, or over-the-counter (OTC) at home use  

Hypertension Machine Learning-Based Notification Software (SFR) 

In contrast, devices classified under FDA product code SFR are blood pressure notification devices. These do not provide exact blood pressure readings; instead, they indicate the presence, absence, or likelihood of hypertension. The software does not diagnose hypertension.  

These devices utilize software and machine learning techniques that analyze non-invasive physiological inputs to identify potential hypertension and indicate when further referral or diagnostic follow-up is needed. 

Key Characteristics of SFR Devices: 

• Do not provide specific measurement values (e.g., no systolic/diastolic numbers) 

• Offer notifications or alerts suggesting that blood pressure may be higher than normal 

• Used for OTC, wellness, or general health awareness  

• Not intended to replace traditional diagnostic methods or serve as a primary tool for ongoing blood pressure monitoring and treatment 

Why the Difference Matters 

The distinction between measurement and notification devices goes beyond regulation—it defines their intended use, clinical validation requirements, and the level of evidence needed to demonstrate substantial equivalence for FDA 510(k) submission.  

Feature	Measurement Device (DXN)	Notification Device (SFR)
Regulated as a medical device	✅ Yes	✅ Yes
Regulation Number	870.1130	870.2380
Device Class	Class II	Class II
Provides numeric readings	✅ Yes	❌ No
Clinical Testing	✅ Yes - Requires ISO 81060-2 / ISO 81060-7 validation protocols	✅ Yes - Unique clinical verification protocols and longitudinal studies
Statistical End Points	Mean Error and Standard Deviation	Sensitivity and Specificity

Understanding this difference helps developers plan appropriate validation strategies, manage CRO partnerships, and avoid regulatory setbacks during submission. 

Implications for Developers and Regulatory Teams 

For developers, early clarity on classification can prevent FDA submission delays and protocol misalignment. Teams should align their device claims with their intended use and deciding whether they aim for a clinical-grade product (DXN) or a software notification tool (SFR). 

Partnering with a regulatory-grade CRO experienced in ISO 81060-2 studies and GCP-compliant protocols can help ensure accurate data generation and regulator-ready endpoints. 

Conclusion: Precision Begins with Classification 

The growing integration of blood pressure sensing into wearable technologies is expanding access to cardiovascular insights. Whether a device measures or merely notifies, defining its classification early ensures efficient development, compliant validation, and ultimately, user trust.  Collaborate with PRL to ensure your device meets FDA expectations through rigorous, clinical testing and clear regulatory alignment. 

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